This invention relates to a display apparatus having a lateral display area, and more particularly, to a display apparatus having a display unit capable of displaying a horizontally and vertically long image constituted by graphic and character patterns.
Image data such as document and drawing data used in a large amount are generally processed and filed by a document file apparatus. The image data is read from an original by a two-dimensional scanning device and is stored in, e.g, an optical disk. The image data is arbitrarily retrieved and read out from the optical disk. Such a document file apparatus is very popular. In this apparatus, the image data read by the two-dimensional scanning device or read out from the optical disk is displayed on a CRT (cathode-ray tube) display unit as a display apparatus. Such CRT display units used are classified into vertical (i.e., the dimension along the vertical direction is larger than that along the horizontal direction) and horizontal (i.e., the dimension the along horizontal direction is larger than that along the vertical direction) type CRT display units.
A conventional document file apparatus uses a vertical or lateral CRT display unit, but applications (i.e., rows.times.columns) of characters displayed on the vertical and horizontal type display units differ from each other. For this reason, even if the circuit components of the document file apparatus for the vertical and horizontal type display units are identical, different applications for the vertical and horizontal type display units must be developed. Since different character application programs are developed for the vertical and horizontal display units in document file apparatus including identical components except for the display units, the high cost and long time are undesirably required to develop application software for the vertical and horizontal character applications.